Mobility-Enhancing Blood Pump System

ABSTRACT

A blood pump system includes a first implantable housing, an implantable blood pump independent from the first implantable housing, and a percutaneous extension. The first implantable housing includes a rechargeable power storage device. The implantable blood pump supplements the pumping function of a heart. The rechargeable power storage device supplies electrical power to the implantable blood pump. The percutaneous extension is coupled to the rechargeable power storage device and adapted to traverse the skin. The percutaneous extension is configured to releasably connect to an external power supply adapted to provide power for recharging or supplementing the rechargeable power storage device to power the implantable blood pump.

TECHNICAL FIELD

This document relates to implanted medical pump systems, such asventricular assist pumps, and components, such as controllers andbatteries associated with the pump systems.

BACKGROUND

The human heart is a complex and critical pump. Due to variouspathologies, the heart can become dysfunctional, acutely or chronically.When damage to the heart becomes sufficiently symptomatic by clinicalmeasures, the heart may be diagnosed as cardiomyopathic, a form of heartfailure. In such a situation, a doctor can recommend mechanicalassistance among the few therapeutic options that include pharmacologictherapy and heart transplantation. Where an afflicted person isscheduled to receive a transplant, mechanical assistance may be a choiceof therapy until a donor heart becomes available.

Blood pumps are commonly used to provide mechanical augmentation to thepumping performed by the left and/or right ventricles of the heart.Ventricular assistance may be provided by an implantable pump that isconnected in parallel with the person's heart and may be regulated by acontroller. The controller and the pump use a power source, such as oneor more external batteries or electrical connection to a wall socket. Ablood pump generally uses about 1-10 W of power. Connection to asufficient power source to operate the pump and controller can makemobility difficult, which can reduce the quality of life for a patient.

SUMMARY

A blood pump system is described that includes a first implantablehousing, an implantable blood pump independent from the firstimplantable housing, and a percutaneous extension. The first implantablehousing includes a rechargeable power storage device. The implantableblood pump supplements the pumping function of a heart. The rechargeablepower storage device supplies electrical power to the implantable bloodpump. The percutaneous extension is coupled to the rechargeable powerstorage device and adapted to traverse the skin. The percutaneousextension is configured to releasably connect to an external powersupply adapted to provide power for recharging or supplementing therechargeable power storage device to power the implantable blood pump.

The first implantable housing can have a volume that ranges from about 1in³ to about 20 in³. For example, the first implantable housing can havea volume that ranges from 7 in³ to 13 in³. In some embodiments, theimplantable housing has a volume of about 10 in³. By having the firstimplantable housing independent from the blood pump, the housing can besized to include a larger power storage device having a larger powerstorage capacity, which can extend the length of time that the bloodpump can be operated with power supplied from the power storage device.In some embodiments, the rechargeable power storage device can supplyelectrical power for normal operation of the blood pump for a period oftime of at least 30 minutes. In some embodiments, the rechargeable powerstorage device can supply electrical power for normal operation of theblood pump for a period of time of at least 2 hours. In someembodiments, the rechargeable power storage device can supply electricalpower for normal operation of the blood pump for a period of time of atleast 3.5 hours. In some embodiments, the rechargeable power storagedevice can supply electrical power for normal operation of the bloodpump for a period of time of about 5 hours. In some embodiments, therechargeable power storage device can be recharged from a functionallydepleted state to a fully charged state in less than about 1 hour.

The first implantable housing can further include an implantedtelemetering device. For example, the system further includes anexternal monitoring device that includes an external telemetering devicethat communicates wirelessly with the implanted telemetering device. Insome embodiments, one of an internal system controller and an externalmonitoring device is adapted to notify the patient that an amount ofelectrical charge remaining in the rechargeable power storage device isless than a minimum threshold (e.g., by vibrating, by light, by sound).The minimum threshold can be the amount of electrical charge normallyused for normal operation of the blood pump, e.g. 30 minutes. In someembodiments, the first implantable housing is adapted to vibrate tonotify the patient that the amount of electrical charge remaining isless than the minimum threshold.

The system can include two rechargeable power storage devices thatsupply electrical power to the blood pump. The second rechargeable powerstorage device can be within the first implantable housing or, in otherembodiments, within a second implantable housing. In some embodiments, asecond implantable housing encloses the blood pump and includes pumpcontroller circuitry that controls the operation of the blood pump. Thesystem can include a rechargeable battery electrically connected to thepump controller circuit for supplying electrical power to the pumpcontroller circuit.

The percutaneous extension can include a plurality of wires thattraverse the skin and carry electrical current to recharge or supplypower to the rechargeable power storage unit. In some embodiments, thepercutaneous extension has a cross-sectional area that is less thanabout 0.1 in². The percutaneous extension can also include an electricalconnector coupled to the plurality of wires and adapted to couple to aportion of the external power supply. In some embodiments, thepercutaneous extension includes at most four wires. In otherembodiments, the percutaneous extension includes more than four wires.For example, the percutaneous extension can include two redundant setsof two wires, wherein each redundant set of wires can carry electricalcurrent to recharge the rechargeable power storage unit.

The percutaneous extension can include a fluid-resistant sheath that iscoupled to the electrical connector and that surrounds the plurality ofwires along substantially the length of the plurality of wires. In someembodiments, the percutaneous extension can include a fluid resistantcap adapted to be removably coupled to the electrical connector forprotecting the interior of the electrical connector from contact withexternal fluids when the electrical connector is not coupled to aportion of the external power supply. In some embodiments, the systemincludes an internal power sensing feature that detects an amount ofpower remaining in the rechargeable power storage device and a cap or anexternal end of the percutaneous extension is adapted to emit a lightwhen the power sensing feature determines that the amount of powerremaining in the rechargeable power storage device is less than aminimum threshold.

The system can include an internal system controller that controls theoperation of the blood pump. In some embodiment, an internal systemcontroller can be included in the first implantable housing.

The system can also include an external power supply. The external powersupply can be, for example, a battery or a converted AC source. Theexternal power supply can be adapted to supply electrical power for thenormal operation of the blood pump.

The blood pump can be a ventricular assist device (e.g., an LVAD).

The system can be implanted in a user and used for mechanical assistanceto the user's heart and/or to replace the heart. The user can connectthe percutaneous lead to an external power supply to supply power to theblood pump or to charge the rechargeable power storage device. The usercan also disconnect the percutaneous lead from the external power supplyfor a period of at least 30 minutes, during which the rechargeable powerstorage device supplies power to the heart pump. The user can thenreconnect the percutaneous lead to the external power supply to rechargethe power storage device or to supply power to the blood pump.

In another aspect, the system includes an implantable blood pump thatsupplements the pumping function of a heart, an internal systemcontroller that controls the operation of the implantable blood pump, arechargeable power storage device that supplies electrical power to theimplantable blood pump and is adapted to supply electrical power for thenormal operation of the implantable blood pump for a period of time ofat least 30 minutes, and a percutaneous extension coupled to therechargeable power storage device adapted to traverse the skin and toreleasably connect to an external power supply to provide power tosupplement or recharge the rechargeable power storage device. In someembodiments, the rechargeable power storage device has a volume that isgreater than about 7 in³.

In another aspect, the system includes a first implantable housingincluding an internal system controller and a rechargeable power storagedevice, a blood pump that supplements the pumping function of a heart,and a percutaneous extension. The first implantable housing is coupledto the blood pump via one or more electrical wires, and the rechargeablepower storage device supplies electrical power to the blood pump for thenormal operation of the blood pump for a period of not less than 30minutes. The system also includes an external device that wirelesslycommunicates with the internal system controller. The percutaneousextension is adapted to traverse the skin and to releasably connect toan external power supply to provide power to the rechargeable powerstorage device. The percutaneous extension includes two redundant setsof two wires. Each redundant set of wires is adapted to carry electricalcurrent to recharge the rechargeable power storage unit. Thepercutaneous extension also includes an electrical connector coupled tothe plurality of wires and adapted to couple to a portion of theexternal power supply. The percutaneous extension also includes awater-resistant sheath that is coupled to the electrical connector andthat surrounds the plurality of wires along substantially the length ofthe plurality of wires. In some embodiments, the percutaneous extensionhas a cross-sectional area that is less than about 0.1 in². In someembodiments, the first implantable housing has a volume that ranges fromabout 1 in³ to about 20 in³.

The blood pump system can be configured with features to decrease thepossibility of infection. The percutaneous lead can be configured tohave a smaller diameter, thus lowering the possibility of infectionaround the skin opening through which the percutaneous lead passes. Witha percutaneous lead that can be used for recharging the internal powerstorage devices, other more cumbersome power transfer methods, such astranscutaneous power transfer, can be avoided. Since transcutaneouspower systems require the formation of large surgical pockets within thepatient to hold the associated equipment, such as energy transferringcoils, systems that do not include a transcutaneous power transfersystem reduce the possibility of infection in and surrounding thepockets. Furthermore, systems that incorporate a percutaneous lead forpower transfer advantageously reduce power losses during transfer andeliminate tissue heating, when compared to systems incorporatingtranscutaneous power transfer.

The details of one or more embodiments are set forth in the accompanyingdrawings and the description below. Other features, objects, andadvantages will be apparent from the description and drawings, and fromthe claims.

DESCRIPTION OF DRAWINGS

FIG. 1 is a front view depicting one embodiment of a mobility-enhancinghybrid ventricular assist system implanted in a patient and an externalcommunication device.

FIG. 2 is a front view depicting one embodiment of a mobility-enhancinghybrid ventricular assist system implanted in a patient, the hybridsystem including a blood pump, a controller, rechargeable power storagedevices, and a compact percutaneous lead.

FIG. 3A is schematic representation of one embodiment of amobility-enhancing hybrid ventricular assist system including acontroller assembly and a power storage assembly, each separate from theblood pump.

FIG. 3B is schematic representation of another embodiment of amobility-enhancing hybrid ventricular assist system connected to anexternal power source.

FIG. 4 is a cross-sectional view of one embodiment of a compactpercutaneous lead with two sets of redundant power leads.

FIG. 5 is a schematic representation of one embodiment of an implantablecontroller with two unequal capacity rechargeable storage devices.

FIG. 6 is a schematic representation of one embodiment of amobility-enhancing hybrid ventricular assist system including a bloodpump, a controller, rechargeable power storage devices, and a compactpercutaneous lead.

FIG. 7 depicts a front view of one embodiment of a mobility-enhancinghybrid ventricular assist system implanted in a patient with the hybridsystem connected to an external controller and external batteriescontained in a carrier system.

FIG. 8 depicts a front view of one embodiment of a mobility-enhancinghybrid ventricular assist system implanted in a patient with the hybridsystem connected to external batteries contained in a carrier system andin wireless communication with an external interface.

Like reference symbols in the various drawings indicate like elements.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

An exemplary hybrid blood pump system generally includes a blood pump,at least one internal rechargeable power storage device, and apercutaneous lead. The hybrid blood pump system is configured to enhancethe freedom and mobility of the user by allowing for normal function ofthe blood pump when the user is disconnected from an external powersource. The internal rechargeable power storage device can storesufficient power to provide for the normal operation of the blood pumpfor an extended period of time (e.g., at least about 30 minutes andideally at least 2 hours). The percutaneous lead allows for thepercutaneous transfer of power from an external source to normallyoperate the blood pump and to recharge the internal power storagedevice. The hybrid system, which can run on power supplied by either aninternal rechargeable power storage device, or by a direct connectionwith an external power source via the percutaneous lead, provides asystem that allows for increased mobility while avoiding problemsassociated with fully implanted systems that transfer powertranscutaneously. Exemplary hybrid systems are described below inconnection with the attached figures.

FIG. 1 is a front view depicting an example of a mobility-enhancinghybrid ventricular assist system 10 including an internal blood pumpassembly 100, an internal controller assembly 200 connected to the bloodpump assembly via an electrical conduit 230, internal rechargeable powerstorage device(s) 350 contained within the controller assembly 200 (seeFIG. 2), and a percutaneous lead 400 connected to the controllerassembly 200 and exiting the body. The power storage device(s) 350include one or more “smart” lithium-chemistry batteries that are readilyrechargeable. An external monitoring device 500 can perform wireless2-way communication with the internal components of the hybrid system10, for example, via wireless telemetry device 220 (see FIG. 2). FIG. 2is a close-up of the system of FIG. 1, not showing the externalmonitoring device 500 but showing exemplary internal components of thecontroller assembly 200. As depicted in FIG. 1, the internal pumpassembly 100 can also include an implantable blood pump 110 fluidlyconnected to an internal chamber of a heart and circulatory system, anda programming wand 510 included in the external monitoring device 500for communication with the controller assembly 200. The programming wandcan include a built-in display 512 for displaying menus, data, and thelike, and a external wireless telemetry device 514 for communicatingwith the internal telemetry device 220 and one or more user-selectablebuttons 516 (e.g., four buttons in this embodiment).

Blood Pump

The blood pump 110 can be a ventricular assist device (VAD). A VAD is amechanical circulatory device that is used to partially or completelyreplace the function of a failing heart. Some VADs are intended forshort term use, typically for patients recovering from heart attacks orheart surgery, while others are intended for long term use (e.g.,months, years, and the remainder of a user's life), typically forpatients suffering from congestive heart failure. VADs are designed toassist either the right (RVAD) or left (LVAD) ventricle, or both at once(BiVAD). VADs can be designed with an axial flow or centrifugal flowconfiguration. The former can be configured with an impeller suspendedby journal bearing such as a ball and cup, or by magnetic orhydrodynamic forces. The latter can be configured with an impellersuspended by at least magnetic forces, hydrodynamic forces, or acombination of both. In other embodiments, the blood pump can be anartificial heart, which is designed to completely take over cardiacfunction and may require the removal of a patient's heart. It should beappreciated that the technical features disclosed herein apply equallyto any variation of the blood pump as described in this disclosure.

As depicted in FIG. 1, a hybrid ventricular assist system 10 can includethe internal pump assembly 100 connected in parallel with the leftventricle of a heart such that the pump assembly 100 can mechanicallyaugment the pumping of blood performed by the left ventricle. Inparticular, FIGS. 1 and 2 depict the internal pump assembly 100including the blood pump 110, such as the HeartMate® II LVAD, a productof the Thoratec® Corporation of Pleasanton, Calif., while FIGS. 7 and 8depict the pump assembly 100 that includes a different embodiment of anLVAD. For example, the pump assembly 100 can be installed to temporarilyprovide mechanical assistance while an individual waits for atransplant. In other examples, the pump assembly 100 can be implanted toreduce the stress on a person's heart, allowing it to heal and regainnormal function, and later be removed. In yet other examples, the pumpassembly 100 can be implanted as a substantially permanent option.

The blood pump can include internal pump control circuitry. Internalpump control circuitry can also be included in a separate housing (e.g.,with internal rechargeable power storage device). Internal pump controlcircuitry functions to make the blood pump pump when power is suppliedto the blood pump and is distinct from a controller that may alter thepumping operation, alter how power is being supplied to the blood pumpand/or perform other functions for the system, such as detecting whetherthe system is being provided with power from an external power sourceand detecting whether the internal rechargeable power source needs to berecharged from the external power source.

Internal Power Storage Device(s)

One or more power storage devices 350 can be included in a singlehousing. In some embodiments, this single housing also includes acontroller device 210. As depicted in FIGS. 1, 2, and 3B, a controllerdevice 210 and the power storage device(s) 350 can be within the singlecontroller assembly 200. As depicted in FIG. 2, a controller assemblycan include two (or more) power storage devices 350. In otherembodiments, the controller assembly can include a single power storagedevice, or any number of power storage devices. In still otherembodiments, such as depicted in FIGS. 3A, 7, and 8, the hybrid system10 can include one or more housings, separate from the controllerassembly, each containing one or more power storage devices.

As depicted in the FIGS. 1 and 2, the power storage device(s) 350 can beimplanted in a location separate from the blood pump assembly 100, forexample, in the thorax or the abdomen of a patient. In particularexamples, the housing can be implanted in the abdominal quartet, belowthe thorax, within the mussel layers. In other embodiments, the powerstorage device(s) 350 can be implanted in other body locations, such aswithin the leg of a patient. A housing containing the power storagedevice(s) 350 can be positioned and shaped to maximize the dissipationof heat from the power storage device(s) 350. For example, the housingcan be positioned to maximize the amount of blood circulating around thehousing. Accordingly, it can be advantageous to implant the housingcontaining the power storage device(s) 350 at or near the core of thepatient. Implanting the power storage device(s) 350 within a housing ina location separate from the blood pump assembly 100 can allow for theuse of a larger power source than can normally be accommodated withinthe blood pump assembly. It can be desirable to limit the volume ofdevices implanted adjacent to the heart. As such, a battery implantedinside or in close proximity to a blood pump assembly 100 is limited insize, and thus electrical capacity. To allow for a longer period of timein which the user is not connected to an external power source, thepower storage device(s) can be advantageously included in a locationseparate from the blood pump assembly. Locations such as the abdomen maybe able to accept larger implanted devices, and thus allow for largerpower storage device(s), which can be used to increase the period oftime that the internal blood pump can function normally without beingcoupled to an external power source. Moreover, having the power storagedevice(s) 350 in a location separate from the blood pump assembly 100can reduce the probability of heat from the internal power storagedevice(s) damaging the heart and/or tissue adjacent the heart.Furthermore, a location of the power storage device separate from theblood pump assembly allows for outpatient replacement of the powerstorage device, if necessary. Thus, a location can also be selected inaccordance with the level of ease in which the power storage device canbe replaced.

The total volume of the power storage device(s) 350 can be 1 in³ orgreater. In some embodiments, the total volume of a housing includingthe power storage device(s) is between about 1 in³ and about 20 in³. Insome embodiments, the power storage device(s) are designed with variousoptions based on size and run time, including but not limited toproviding greater than 30 minutes of blood pump normal operation,greater than 1 hour of blood pump normal operation, greater than 2 hoursof blood pump normal operation, and greater than 3.5 hours of blood pumpnormal operation. The housing can, in preferred embodiments, have avolume of between 5 in³ and 13 in³ (e.g., about 10 in³). The totalvolume of a housing would also depend on the material used and thebattery technology. Generally, there is a tradeoff between size and runtime. For instance, the larger the rechargeable power source the largerthe charge storage capacity and thus the longer the run time. However,there is also a higher risk of infection. On the other hand, the smallerhousing containing a smaller rechargeable power source would have asmaller charge storage capacity, a shorter run time, but a lower risk ofinfection.

The housing, like most implanted components, can be hermetically sealed.The housing can be made of commercially available inert materialsincluding both biocompatible metals, biocompatible polymers, andbiocompatible ceramics, such as stainless steel, titanium and titaniumalloys (e.g., Ti-6Al-4V grade 5 titanium), cobalt-chromium alloys,polyethylene (e.g., UHMWPE), PEEK polymers, and combinations thereof.The housing material can also be selected for its ability to dissipateheat as well as its ability to provide an electrical and/or magneticshield should it be used to house an internal controller. The housingcan be substantially flat. For example, the housing can have a thicknessof about 0.3 to 1 inch, a width of about 1.5 to 3.5 inches, and a lengthof about 3 to 6 inches. In some embodiments, the housing has dimensionsapproximating the dimensions of a standard cigarette pack (about 2.6inches×about 4.6 inches×about 0.6 inches). In some embodiments, thehousing can have a slightly curved configuration bent to confirm to thecontours of a human abdomen, similar to a whisky flask. The housing canalso have rounded corners. This can allow a user to have increasedfreedom of movement because batteries of this volume can be used toprovide power for normal pump operation for extended periods of timewithout the use of an external power supply. A flat configuration canallow for a more superficial placement and replacement, if necessary. Aflat configuration can also facilitate the dissipation of heat. Thehousing can also have rounded corners and other features to reduceinjury to surrounding tissue. An outer surface of the housing can havinga coating or other features that reduce the instances of pocketinfection.

As the pump is directly connected to the heart, the size of the implantadjacent to the heart should be minimized. As the size of the implantincreases, so does the risk of a pocket infection. If the pump pocketbecomes infected, the infection could enter the blood stream causingsepsis, which can be extremely hazardous to an alreadyimmuno-compromised patient. An implant of minimal size adjacent to theheart can allow for placement of the device entirely within the thoraxwhich may simplify the surgery and allow for a shorter recovery time.

The power storage device(s) 350 can be one or more rechargeablebatteries. For example, the power storage device(s) 350 can be one ormore lithium ion batteries. In other embodiments, the power storagedevice(s) 350 can be one or more lithium polymer batteries. In otherexamples, the power storage device(s) 350 may comprise a capacitordevice capable of being recharged over time and discharging powersufficient for normal operation of the system 10. Still, fuel celltechnology using hydrogen as an energy storage vehicle may provide aviable option, using electricity provided by an external power source toelectrolyze water within the body to generate additional hydrogen.Still, other high density power storage devices may be developed in thefuture and can be used in as the power storage device(s) 350 asdescribed herein.

Because some batteries may become non-rechargeable if fully depleted,some batteries, such as “smart” lithium-polymer batteries, can includeinternal circuitry that prevents the batteries from becoming fullydepleted. As such, if the charge level within such a battery falls belowa predetermined level, this internal circuitry can cause the battery tostop delivering power to avoid irreversibly damaging the battery.Accordingly, if the charge within a battery falls below thispredetermined level, the battery is functionally depleted. As analternative, the controller device 210 can determine whether the energyremaining in a particular power storage device 350 has fallen below apredetermined threshold and can stop transferring power from a powerstorage device 350 if the remaining energy falls below thatpredetermined threshold. Still, another possibility is to have thecontroller device 210 send a warning signal when the power capacitydrops below a certain level and into a range where operation of the pumpis still possible, but before it is considered functionally depleted.

When connected to an external power source, the internal power storagedevices 350 can be recharged using energy from the external powersource. Charge time can depend on the size of the battery and the chargerate limitations for heat dissipation in the charge electronics and theheat dissipation in the percutaneous lead. For example, power storagedevices can be recharged in 50% to 400% of the discharge time. In someembodiments, the internal power storage devices can be recharged from afunctionally depleted state to having a full charge in less than 30minutes.

Percutaneous Lead

As shown in FIGS. 1 and 2, the percutaneous lead 400 can include aproximal end 402 located internal to the user and a distal end 404located external to the user, with a portion 406 that traverses theskin. The proximal end 402 can be electrically connected to thecontroller assembly 200 and the distal end 404 can be removably coupledto an external power supply (not shown). A cap 410 can be used toprotect the external physical structure of the distal end 404 andconnector, as well as the exposed metal connections that can be coupledto the external power supply. In some embodiments, this cap can bedesigned to be fluid resistant (or fluid proof). In some embodiments,the cap can prevent moisture from seeping into the connector andreaching the metal connections. The cap can also to prevent anyelectrical conduction from any outside element with the metalconnections. In some embodiments, the cap can be waterproof and fluidresistant. The cap structure can be made of a metallic or non-conductingmaterial; in either case, the cap design will have insulation to preventshorting of the metal connections or conduction of electricity betweenan external source and the metal connections. When connected to anexternal power supply, power sufficient for the normal operation of thehybrid system 10 and to charge the power storage device(s) 350 can betransferred through the percutaneous lead 400 by redundant power andground lines. When the percutaneous lead is disconnected from anexternal power supply, power for the normal operation of the hybridsystem 10 can be supplied by the internal rechargeable power storagedevice(s) 350.

The distal end 404 of the percutaneous lead 400 can be electricallycoupled to an external power source. In these circumstances, theexternal power source can supply power for normal operation of theinternal components of the hybrid system 10 (e.g., the pump assembly100, the controller assembly 200, and the like) and to recharge thepower storage device(s) 350. The external power source can be in theform of external batteries, an external power source plugged into atraditional wall socket such that it can convert AC electricity to DCelectricity, and the like. For example, when the percutaneous lead 400is coupled to an external power source that is plugged into a wallsocket, the user is limited in the distance that he can travel. In thesecircumstances, the user may be limited to a single room, a singlebuilding, and the like. Furthermore, due to the connection of thepercutaneous lead 400 to the external power source, the user may belimited from performing activities requiring a high degree of freedom ofphysical movement and/or that involve exposure to liquids, including butnot limited to daily activities such as taking a bath, grocery shopping,physical and sporting activities like swimming, golf, tennis, etc., andhousehold maintenance.

To increase a user's freedom of movement, the hybrid ventricular assistsystem 10 can be configured to be electrically coupled via thepercutaneous lead 400 to a portable external power source, such asexternal batteries. For example, FIGS. 7 and 8 depict a portable systemfor carrying external batteries. When the percutaneous lead is connectedto a portable external power source, the user can experience improvedmobility, comfort, independence, and self-esteem when compared to beingcoupled to a power source plugged into a wall socket. For example, theuser can wear a garment that is designed to contain rechargeablebatteries such that the user is free to perform household chores, travelto the grocery store, go on a walk, etc. When coupled to externalbatteries worn as part of a garment, a user is not restricted by a cordplugged into a wall and is free to partake in many normal day-to-dayactivities, thus leading to increased independence and self-esteem.Additionally, since the external power source is worn with the user, thepossibility of pulling on the percutaneous lead and damaging surroundingtissue is reduced, leading to a decreased possibility of infection andincreased comfort.

To further increase a user's freedom of movement, the hybrid ventricularassist system 10 can be used for extended periods of time without theuse of an external power supply. For example, when a user desires tohave a greater freedom of movement and comfort, the user can disconnectthe distal end 404 of the percutaneous lead 400 from an external powersource, thus freeing him from the limitations imposed by such anexternal power source. While disconnected from the external powersource, the internal power storage device(s) 350 can supply the powerfor the normal operation of the hybrid system 10 (e.g., the pumpassembly 100, the controller assembly 200, and the like) for an extendedperiod of time (e.g., greater then 30 minutes, greater than 1 hour,greater than 2 hours, greater than 3.5 hours, and the like, based on thesize and capacity of the internal power storage device 350). Whileunplugged from all external power sources, the user experiences greaterfreedom to take part in physical and passive activities, such asswimming and bathing, that would otherwise be complicated by externalcords, batteries, and the like.

When the percutaneous lead 400 is reconnected to an external powersource, the external power source can be used to not only support normaloperation of the hybrid system 10, but also to recharge the internalpower storage device(s) 350. Using the percutaneous lead 400 to transferenergy from an external power source allows for a greater power transferefficiency, and thus faster recharge rate, than a transcutaneous powertransmission system. In some embodiments, the internal power storagedevice(s) can be advantageously recharged from a functionally depletedstate to a fully recharged state in less than 30 minutes.

As previously referenced, a blood pump system can use a transcutaneouspower system to wirelessly transfer power from an external power sourceto components implanted in a user. For example, power can be transmittedfrom the external source to the internal components by generating amagnetic field in the external coil and converting the magnetic field toelectrical power in the internal coil, which is distributed to the otherinternal components. However, transcutaneous power systems can belimited in the rate of power transferred, for example, by the size ofthe coils. To increase the rate at which the power storage device(s) arecharged, larger coils can be used. However, larger coils occupyadditional internal space, which can result in an increased possibilityof infection, and can result in the user carrying additional externalequipment. Smaller coils, however, have slower transfer rates.Furthermore, transcutaneous power transmission can lose power duringtransmission, some of which is lost as heat within the tissuesseparating the internal and external transmission coils. This heatingcan be damaging to tissue. Additionally, due to energy lost duringtransmission, a user wearing external batteries, each with a fixedenergy capacity, would have less time in between battery changes whenusing a transcutaneous power transfer system when compared totransferring power via the percutaneous lead 400. Also, fixation of thecoils is critical for maintaining optimal alignment. As the coils becomemore decoupled (i.e. through misalignment and/or separation), efficiencyof the transfer drops.

The percutaneous lead 400 can, in some embodiments, have a crosssectional area of less than about 0.10 square inches (e.g., a diameterthat is less than about 0.3 inches). When using a reduced-diameterpercutaneous lead 400, a smaller opening in the user's skin is used toaccommodate the percutaneous lead 400. Reducing the diameter of thepercutaneous lead that traverses the skin of the user has the beneficialeffect of exposing less tissue, thus decreasing the possibility ofinfection around this opening. While a larger diameter percutaneous leadcan increase transfer of both power and data to the internal components,a reduction in the diameter of the percutaneous lead can be achieved byusing the percutaneous lead to only transfer power. The use of highlyconductive materials in the percutaneous lead can be used to offset thesmaller diameter, or the reduced cross-sectional capacity of theconductors. Accordingly, in some embodiments, control data istransmitted via wireless communication, thus allowing for a reduction inthe diameter of the percutaneous lead 400. In comparison, exemplarypercutaneous leads that include redundant sets of wires for transferringboth power and data can have diameters that exceed 0.75 inches indiameter. In other embodiments, for example in ventricular assistsystems lacking an internal controller device 210, a larger diameterpercutaneous lead may be used to reliably transfer both power and datato the internal components. In these examples, the percutaneous lead canhave a diameter that is greater than 0.5 square inches (e.g., greaterthan 0.75 inches in diameter).

FIG. 4 is a cross-sectional view of a compact percutaneous lead 400 withtwo sets of redundant power leads. The percutaneous lead 400 can includea flexible outer housing 408 enclosing redundant electrical lead sets440 and 445, for example as discussed in U.S. patent application Ser.No. 12/472,812, filed May 27, 2009, which is hereby incorporated byreference. In this configuration, electrical energy can be supplied froman external power source to the internal components of the hybridventricular assist system 10 (e.g., the blood pump 110, the controllerdevice 210, the power storage device(s) 350, and the like). Each of thelead sets 440 and 445 can be capable of transferring all of the powerfor normal operation of the hybrid system 10, including recharging ofthe power storage device(s) 350, resulting in fully redundant energytransfer. Thus, if one of the conductors of one of sets 440 and 445becomes damaged such that it is unable to transfer electrical energy,the system 10 can be fully powered by the one set 440 and 445 thatremains intact. Furthermore, if one conductor of each set is damaged,power can be transferred by using non-damaged conductors from each setIn examples where the percutaneous lead 400 contains only the lead sets440 and 445 for transferring energy, the percutaneous lead 400 has asmaller cross-sectional area than in cases where additional wires areincluded for data transfer.

The cross-sectional area of the percutaneous lead 400 can be furtherdecreased by, for example, including only a single set of power transferwires. In other examples, the cross-sectional area of the percutaneouslead 400 may be decreased by decreasing the diameter of the lead sets440 and 445 (e.g., by configuring them such that they are not fullyredundant). In this example, each lead set 440 and 445 may be configuredto carry only a percentage (e.g., less than 100%, 95%, 64%, 50%, and thelike) of the total energy used during normal operation of the system 10and recharging of the power storage device(s) 350. For example, eachlead set 440 and 445 may be configured to supply sufficient power fornormal operation of the hybrid system 10 and to trickle charge the powerstorage device(s) 350. In this example, when both lead sets 440 and 445are functional, the hybrid system 10 can be supplied with power fornormal operation and with sufficient power such that the power storagedevice(s) 350 can be quickly charged (e.g., the power storage devicescan be recharged in less than 60 minutes). In other embodiments, thesystem can have a longer recharge time, depending on the type of powerstorage device and the percutaneous lead. However, if one of the leadsets 440 and 445 becomes non-functional (e.g., the lead set is damagedand becomes unable to transmit power), the system 10 can operatenormally with the exception of charging the internal power storagedevice(s) 350, which will be accomplished at a slower rate. In thisexample, a redundancy is provided for normal operation of the system 10while further reducing the diameter of the percutaneous lead 400, thusfurther decreasing the possibility of infection.

The hybrid ventricular assist system 10 can include other features thatdecrease the cross-sectional area of the percutaneous lead 400 whileallowing for power and data transfer through the lead 400. For example,the lead 400 can include the lead sets 440 and 445 configured totransfer power from a power source external to a user to the internalcomponents of the system 10. Power transferred from an external powersource, for example, can be used for normal operation of the blood pump110 and to recharge the internal power storage device(s) 350. Sincepower for the normal operation of the internal components of the system10 can come from the power storage device(s) 350, power transfer can betemporarily discontinued through one or more of the lead sets 440 and445, thus leaving one or more of the lead sets 440 and 445 available forthe transfer of data. When the data transmission is complete, power onceagain can be transferred through the lead sets 440 and 445. This featurefor the temporary cessation of power transfer can be incorporated intoother percutaneous lead configurations, can be combined with otherlead-size-reducing features, and is not restricted to the four-wirepercutaneous lead depicted in FIG. 4. In some embodiments, thepercutaneous lead includes two non-redundant sets of wires, one set forcharging the power storage device(s) 350 and one set for providing powerto the blood pump. In such an embodiments, a disabled recharging set canbe rerouted to simply provide power to the blood pump.

FIG. 6 is a schematic representation of the mobility-enhancing hybridventricular assist system 10 including the blood pump assembly 100, thecontroller assembly 200, the rechargeable power storage devices 350 and355, and the compact percutaneous lead 400. The hybrid system 10 can beconfigured to reduce the diameter of the percutaneous lead 400. In someembodiments, the hybrid system 10 includes internal controller assembly800 that can control functions of the hybrid system 10 and canwirelessly communicate with external components. Due at least in part tothe presence of the internal controller assembly 800, data communicationbetween the internal controller assembly 800 and external components canbe transmitted in a manner other than through the percutaneous lead 400.Since the percutaneous lead 400 can be limited to the transfer ofelectrical energy, the resulting diameter of the percutaneous lead 400can be smaller than if data transfer also took place through thepercutaneous lead 400. For example, the controller device 210 can beelectrically connected to the two power storage device(s) 350 and 355with lead sets 860 and 861, respectively, and to the wireless telemetrydevice with redundant data lead sets 862 and 863. Furthermore, thecontroller device 210 can be electrically connected to the pump assemblywith two redundant power lead sets 864 and 865 and two redundant datalead sets 866 and 867. In this example, the internal controller 210 iselectrically connected to the pump assembly 100 by eight wires, but onlyfour wires are used in the percutaneous lead 400. In examples where acontroller device is external to the patient, additional wires may beused in the percutaneous lead that traverses the skin of the user.

The percutaneous lead 400 can additionally include other features thatreduce a user's possibility of infection. As described above, an openingin the skin exposes tissue to infection. Additionally, movement of theportion 406 of the percutaneous lead 400 that traverses the skin openingin relation to the skin opening itself can cause damage to tissuesurrounding the percutaneous lead 400, thus increasing the possibilityof infection. The hybrid system 10 can be configured to include featuresthat reduce movement of the internal portion of the percutaneous lead400 relative to the user. For example, as depicted in FIGS. 1 and 2, thepercutaneous lead 400 can include a strain-relief portion 420 foranchoring the percutaneous lead 400 to the user and for reducing thestrain on the portion of the percutaneous lead exiting the user's body.In another example, the percutaneous lead 400 can include a low-forcebreakaway portion 430 that can separate when subjected to a pullingforce that is less than the force expected to cause damage to the tissuesurrounding the skin opening. Due to the presence of the internal powerstorage device, the percutaneous lead does not act as a lifeline, thus abreakaway connection can be used because an accidental disconnectionwill not result in a loss of power to the blood pump. When the distalend 404 of the percutaneous lead 400 is pulled with a force greater thanthe break-away force of the breakaway portion 430, the percutaneous lead400 can reversibly separate into two portions, thus reducing the strainon the portion of the percutaneous lead 400 entering the skin opening.The two portions can be re-joined at the breakaway portion 430 when thestress on the breakaway portion 430 falls below the break-away force.While the percutaneous lead 400 is separated into the two portions,sufficient power to maintain normal operation of the hybrid system 10can be supplied by the internal power storage device(s) 350. When thepercutaneous lead 400 is reconnected, power to maintain normal operationof the hybrid system 10 can once again be supplied by the connectedexternal power source, while also recharging the internal power storagedevice(s) 350.

The percutaneous lead can be connected to the external power source byuse of a connector. For example, the connector can be flat, square,round, or any other shape. The connector can provide a fluid resistantor fluid proof connection. In some embodiments, the connector canprevent liquid water proof and water vapor proof.

Controller

The blood pump can be controlled by internal control circuitry. In someembodiments, the control circuitry can be a part of the blood pumpassembly 100. In other embodiments, the control circuitry (e.g.,controller device 210) can be within the same housing containing therechargeable power storage device(s) 350, as depicted in FIGS. 1, 2, and3B. In other embodiments, control circuitry can be within a dedicatedimplantable housing separate from both the blood pump assembly 100 andthe housing containing the rechargeable power storage device(s) 350, asdepicted in FIGS. 3A, 7, and 8. Internal control circuitry (e.g., thecontroller device 210) can in some embodiments communicate with anexternal controller and/or an external input device.

The internal control circuitry can include, but is not limited to, oneor more features to monitor the operation of the hybrid ventricularassist system 10, to monitor the user (e.g., to detect blood pressure),to control predetermined functions of the hybrid system 10 (e.g., tocontrol how power is supplied to the blood pump), and to inform the userof particular information regarding operation of the hybrid system 10(e.g., by vibrating or by sending a signal to an external device). Theinternal control circuitry can include features for controlling thespeed of the pump 110. In another example, the internal controlcircuitry can monitor functions of the system 10, such as the electricalcharge level of (i.e. usable energy remaining in) the power storagedevice(s) 350. In still another example, the internal control circuitrycan inform the user of alerts and alarms pertaining to the operation ofthe hybrid system 10, such as alerting the user when the charge level ofone or more of the power storage devices 350 has fallen below apredetermined threshold, or signaling an alarm when a malfunction in thesystem 10 has occurred. The internal control circuitry can inform theuser of a condition, for example, by initiating an internal vibrator,signaling a remote controller via the wireless telemetry unit 220,causing a light to flash, and the like. For example, in someembodiments, an external portion of the percutaneous lead 400 (e.g., thecap 410, the distal end 404 of the percutaneous lead 400, and the like)can include a light that can flash. For example, if the amount of powerremaining in the internal power supply falls below a threshold and poweris not being supplied to the system through the percutaneous lead, thecontroller can direct power though wires provided in the percutaneouslead 400 to a light in an external portion of the percutaneous lead orin the cap. In yet another example, the controller can monitor the inletand outlet pressures of the pump 110, determine blood flow through thepump assembly 100, determine an activity level of the user and therebychange the speed of the pump, and the like. These controller functionscan also be preformed using an external controller that communicateswith the internal controller, for example using an externalcommunication device that performs wireless 2-way communication. Thecontroller can also detect whether power is being provided through thepercutaneous lead and to control whether that power is used to simplyoperate the blood pump or to also recharge the internal power supply.The internal controller can also include electrical circuitry to detectand shut down (if necessary) failed conductors in the percutaneous leadand/or between the controller and blood pump or other internal housings.This can be accomplished by detecting increased or decreased electricalresistance. In some embodiments, the controller can then use a redundantconductor. The controller can also provide different alarms depending onwhether power is being supplied via the percutaneous lead, and in someembodiments depending on which external power source is active (e.g.,external portable battery versus converted AC power source). Internalalarms can include internal vibrators (e.g., piezoelectric buzzers).External alarms can include lights and/or audible alarms.

The controller can also include a memory buffer to store information.The member buffer can store acquired data, such as pump speed andphysiological data of the patent (e.g., blood pressure). The memberbuffer can also be used to record information about how the pump systemis operating, including error information and/or battery life. Theinformation in the memory buffer can be downloaded to an external systemvia the percutaneous lead and/or via a telemetry system. The memorybuffer can provide a means to record information when the user isdisconnected and/or away from external components.

External Components

The hybrid ventricular assist system 10 can be electrically coupled viathe percutaneous lead 400 to an external power source that can supplypower for normal operation of the hybrid system 10. The external powersource can be external batteries, a wall socket, or the like. Anexternal power source can have different levels of technologicalcomplexity, ranging from a simple AC transformer/adapter to a controlconsole that is used to diagnose, control, and/or modify functions ofthe pump. In some embodiments, the external batteries can be part of orconnected to an external controller, as depicted in FIG. 7. In otherembodiments, such as depicted in FIG. 8, the percutaneous lead 400 canbe directly connected to external batteries. Power supplied by theexternal power source can be used to recharge the power storagedevice(s) 350. As noted above, the hybrid system 10 can also include anexternal controller (e.g., an external controller 500) that can be usedin conjunction with or in lieu of the internal controller device 210.

Referring again to FIG. 1, the hybrid ventricular assist system 10 caninclude the external monitoring device 500 in wireless communicationwith the internal components of the hybrid system 10 (e.g., thecontroller device 210, the wireless telemetry device 220, the pumpassembly 100, and the like). The external controller 500 can include theprogramming wand 510. The programming wand can include the built-indisplay 512 for displaying menus, data, and the like, the externalwireless telemetry device 514 for communicating with the internaltelemetry device 220, and the one or more user-selectable buttons 516(e.g., four buttons in this embodiment) for navigating menus, selectingfeatures, inputting data, and the like.

The external electrical interface can include electronics to detect andshut down (if necessary) any faulty conductors in the percutaneouscable.

Schematics

FIG. 3A is schematic representation of one embodiment of themobility-enhancing hybrid ventricular assist system 10 including acontroller assembly 600 and a separate power storage assembly 300. Asdepicted in FIG. 3A, the hybrid system 10 also includes the internalblood pump assembly 100, one or more rechargeable storage devices (e.g.,the power storage device 350, and the like) included in the powerstorage assembly 300, and the compact percutaneous lead 400. Thecontroller assembly 600 can be implanted in, for example, the thorax,the abdomen, or other parts of a patient and can be electricallyconnected to the pump assembly 100 via the electrical conduit 230 suchthat the controller assembly 600 can control functions of and monitorthe pump assembly 100. The controller assembly 600 can be connected tothe power storage assembly 300 via an electrical conduit 330 and cancontrol charging of the power source contained within the power storageassembly 300. Power for normal operation of the hybrid system 10 can besupplied by the power storage assembly 300. The power storage device350, for example, can be directly electrically connected to thecontroller assembly 600, the pump assembly 100, and the like, and can beimplanted in the thorax, the abdomen, or other parts of the user in alocation separate from those of the controller assembly 600 and the pumpassembly 100. In other embodiments, the power storage device 350 mayindirectly provide power to the pump assembly 100. Power storagedevices, in addition to or in lieu of the power storage device 350, canbe included in one or both of the blood pump assembly 100 and thecontroller assembly 600.

FIG. 3B is a schematic representation of certain embodiments of themobility-enhancing hybrid ventricular assist system 10 connected to anexternal power source 20. The hybrid system 10 can include features thatallow for power to and control of an internal pump without constantconnection to external devices. For example, the hybrid system 10 caninclude the internal controller assembly 200 that includes thecontroller device 210, the wireless telemetry device 220, and the tworechargeable power storage devices 350 and 355. The controller assembly200 can be implanted in a single location (e.g., in the thorax, theabdomen, and the like) with the electrical conduit 230 electricallyconnecting elements contained within the controller assembly 200 (e.g.,the controller device 210, the wireless telemetry device 220, therechargeable power storage devices 350 and 355, and the like) to thepump assembly 100. The electrical conduit 230 can be removably coupledto the controller assembly 200 via the bulkhead connector 202 and to thepump assembly via the bulkhead connector 102. The percutaneous lead 400can be coupled to the controller assembly 200 via a bulkhead connector204. In some embodiments, the electrical conduit 230 has a largerdiameter than the percutaneous lead 400, as the electrical conduit 230includes wires for both the transmission of power and data between thecontroller assembly 200 and the pump assembly 100.

The controller assembly 200 can include the power storage device 350 andthe optional power storage device 355 that are substantially equivalentand that can each supply electrical energy to the individual componentsof the hybrid ventricular assist system 10 (e.g., the controller device210, the wireless telemetry device 220, the pump assembly 100, and thelike). In some examples, the power storage devices 350 and 355 caninclude one or more direct electrical connections to the pump assembly100, while in other examples energy can be transferred to the pumpassembly 100 via the controller device 210. Similarly, energy can betransferred to other components of the hybrid system 10 (e.g., thewireless telemetry device 220 and the like) either directly, or throughintervening components. The hybrid system 10 can be configured such thateach of the power storage devices 350 and 355 is a redundant source ofenergy for all components of the system 10, thus the system 10 canfunction normally even when only one of the power storage devices 350and 355 is supplying energy to the hybrid system 10. Power can also besupplied for normal operation of the hybrid system 10 by an externalpower source (e.g., the external power source 20) when connected to thepercutaneous lead 400. When connected in this manner the internal powerstorage devices 350 and 355 can be charged by the external power source20.

FIG. 5 is a schematic representation of an implantable controllerassembly 700 with two unequal capacity rechargeable storage devices. Thehybrid ventricular assist system 10 can include the internal controllerassembly 700 that includes the controller device 210, the wirelesstelemetry device 220, and rechargeable power storage devices 360 and365. In these embodiments, the controller assembly 700 (including theinternal power storage devices 360 and 365) can be implanted in a singlelocation (e.g., in the thorax, the abdomen, and the like) with theelectrical conduit 230 electrically connecting elements contained withinthe controller assembly 700 (e.g., the controller device 210, thewireless telemetry device 220, the rechargeable power storage devices360 and 365, and the like) to the pump assembly 100. The electricalconduit 230 can be removably coupled to the controller assembly 700 viaa bulkhead connector 702 and the percutaneous lead 400 can be coupled tothe controller assembly 700 via a bulkhead connector 704.

The controller assembly 700 can include the power storage devices 360and 365 that can supply electrical energy to the individual componentsof the hybrid ventricular assist system 10 (e.g., the controller device210, the wireless telemetry device 220, the pump assembly 100, and thelike) and that do not have substantially equivalent electrical energycapacities. As with previously described embodiments, the hybrid system10 can include one or more direct electrical connections from theinternal power storage devices (e.g., the devices 350, 355, 360, 365,and the like) to the pump assembly 100 (see FIG. 2). In other examples,energy can be transferred from the internal power storage devices to thepump assembly 100 via the controller device 210. Similarly, energy canbe transferred to other components of the hybrid system 10 (e.g., thewireless telemetry device 220 and the like) either directly, orindirectly through intervening components. The hybrid system 10 can beconfigured such that each of the power storage devices 360 and 365 is aredundant source of power for normal operation of the system 10, thusthe system 10 can function normally even when only one of the powerstorage devices 360 and 365 is supplying power to the hybrid system 10.However the power storage devices 360 and 365 can be configured to storedifferent amounts of energy. For example, the power storage device 360can be configured with a larger capacity than the power storage device365. When the system 10 is disconnected from an external source, initialpower can be supplied by the power storage device 360 and the powerstorage device 360 can be configured to power the system 10 for a periodof time greater than 30 minutes. When the power storage device 360 is nolonger able to supply sufficient power to normally operate the system10, the controller device 210 can notify the user (e.g., by initiating avibrating alarm, causing the cap 410 to illuminate, sending a signal toan external controller, and the like) that the power storage device 360has been depleted and the system 10 is operating using power suppliedfrom power storage device 365. The power storage device 365 can beconfigured to supply the power for normal operation of the system 10,for example, for a period of 10 minutes, to allow a user to reconnectthe system 10 to an external power supply.

Referring now to FIG. 6, the hybrid ventricular assist system 10 can beconfigured to reduce the diameter of the percutaneous lead 400. In someembodiments, the hybrid system 10 includes internal controller assembly800 that can control functions of the hybrid system 10 and canwirelessly communicate with external components. Due at least in part tothe presence of the internal controller assembly 800, data communicationbetween the internal controller assembly 800 and external components canbe transmitted in a manner other than through the percutaneous lead 400.Since the percutaneous lead 400 can be limited to the transfer ofelectrical energy, the resulting diameter of the percutaneous lead 400can be smaller than if data transfer also took place through thepercutaneous lead 400. For example, the controller device 210 can beelectrically connected to the power storage device 350 and the optionalpower storage device 355 with lead sets 860 and 861, respectively, andto the wireless telemetry device 220 with redundant data lead sets 862and 863. Furthermore, the controller device 210 can be electricallyconnected to the pump assembly with two redundant power lead sets 864and 865 and two redundant data lead sets 866 and 867. In this example,the internal controller 210 is electrically connected to the pumpassembly 100 by eight wires, but only four wires are used in thepercutaneous lead 400. In examples where a controller device is externalto the patient, additional wires may be used in the percutaneous leadthat traverses the skin of the user.

Additional Configurations

FIG. 7 is a front view depicting an embodiment of the hybrid ventricularassist system 10 coupled to a portable external controller 30 and twoexternal batteries 40. In the embodiment depicted here, the hybridsystem 10 includes the internal blood pump assembly 100 (including acentrifugal blood pump 150), an internal controller assembly 900, theinternal rechargeable power storage assembly 300, including one or morerechargeable storage devices (e.g., the devices 350, 360, 365, and thelike), and the compact percutaneous lead 400. The controller assembly900 can be implanted in, for example, the thorax, the abdomen, or otherpart of a patient, and can be electrically connected to the blood pump150 such that the controller assembly 900 can control functions of andmonitor the pump assembly 100 and control charging of the power sourcescontained within the power storage assembly 300. Power for normaloperation of the hybrid system 10 can be supplied by the power storageassembly 300. The power storage assembly 300 can, for example, beelectrically connected to the controller assembly 900, the pump assembly100, and the like, and can be implanted in the thorax, the abdomen, oranother part of the user in a location separate from those of thecontroller assembly 900 and the pump assembly 100. This can allow foroutpatient replacement of the power storage device if necessary.

As described previously, the hybrid ventricular assist system 10 can beelectrically coupled via the percutaneous lead 400 to an externalcontroller and power source. However, when coupled to a non-portablepower source (e.g., a power source plugged into a conventional wallsocket) a user's independence, mobility, and comfort can be limited. Toincrease the user's mobility, the percutaneous lead 400 can be uncoupledfrom the non-portable external controller and power source (not shown)and coupled to the portable external controller 30 and the two externalbatteries 40. When coupled to the external controller 30 and the twoexternal batteries 40, the power for normal operation of the blood pump150 can be supplied by the external batteries 40, thus not decreasingthe energy level contained within the internal power storage assembly300. Furthermore, power supplied by the external batteries 40 can beused to recharge the power storage assembly 300. For example, the usercan wear a garment, such as a holster vest 50 that can include batteryholders 52 such that the weight of the external batteries 40 can besubstantially supported by the shoulders of the user. A waist belt 54can be included with the holster vest 50 to firmly hold the batteryholders 52 (including the coupled batteries 40) and the externalcontroller 30 firmly against the user. With the distal end 404 of thepercutaneous lead 400 coupled to the external controller 30, the user isable to move around untethered, for example, by an external power sourceplugged into a wall socket.

When the percutaneous 400 lead is connected to a portable external powersource such as the external batteries 40, the user can experienceimproved mobility, comfort, independence, and self-esteem when comparedto being coupled to a power source plugged into a wall socket. Forexample, the user can wear a garment (e.g., the holster vest 50, acarrying case, and the like) that is designed to contain therechargeable batteries 40 such that the user is free to performhousehold chores, travel to the grocery store, go on a walk, etc. Whencoupled to the external batteries 40 worn as part of a garment, a useris not restricted by a cord plugged into a wall and is free to partakein many normal day-to-day activities, thus leading to increasedindependence and self-esteem. Additionally, since the external powersource is worn with the user, the possibility of pulling on thepercutaneous lead 400 and damaging surrounding tissue is reduced,leading to decreased possibility of infection and increased comfort.

For an even greater degree of mobility, the user can uncouple thepercutaneous lead 400 from the external controller 40. In somecircumstances, a user may be restricted from performing certainactivities while wearing a garment containing electronic devices. Forexample, certain forms of physical exercise, such as swimming, would bedifficult while wearing a garment containing electronic devices.Furthermore, while being coupled to an external power supply, even aportable one such as batteries included in a garment, could be animpedance and inconvenience for activities such as gardening, a briskwalk, a short game of tennis or golf, etc. As such, a user can uncouplethe percutaneous lead 400 from all external devices, remove the externaldevices (e.g., the holster vest 50, the battery holsters 52, the belt54, the external controller 30, the external batteries 40, and the like)for an extended period of time for performing activities that mightotherwise not be possible. Being connected to an external power source,even a portable battery, can also complicate certain relatively passiveactivities, such as taking a bath, that include exposure to liquids.

FIG. 8 is a front view depicting another embodiment of the hybridventricular assist system 10 coupled to two external batteries 40.Similar to the embodiment described in connection with FIG. 7, thehybrid system 10 can include the internal blood pump assembly 100(including the centrifugal blood pump 150), an internal controllerassembly 1000, the internal rechargeable power storage assembly 300(e.g., not contained within the controller assembly 1000), and thecompact percutaneous lead 400. In the embodiment described here,however, the hybrid ventricular assist system 10 can be free of anexternal wired controller (such as the controller 30 depicted in FIG.7). In these embodiments, an adapter 44 can be coupled to the distal end404 percutaneous lead 400 such that the electrical conduits 41 coupledto each of the external batteries 40 can be electrically connected tothe percutaneous lead 400 (e.g., by coupling the ends 42 of theelectrical conduits 41 to the adapter 44) without the use of an externalcontroller 30. Additionally, an external device (e.g., a PDA 530) can bein wireless communication with the internal controller assembly 1000 forthe purpose of relaying data to the user, indicating to the user thepresence of alerts and alarms, and allowing the user to program certainfeatures of the hybrid system 10. As with the embodiment described inconnection with FIG. 7, the user can attain a greater degree of mobilityby removing the external components to perform activities that mightotherwise not be possible.

Implantation Procedure

Referring again to FIGS. 1-2, prior to implantation, the connectors ofthe pump assembly 100 (e.g., connector 102) and the controller assembly200 (e.g., connectors 202 and 204) can be capped to protect theconnectors from contaminants. In some embodiments, a pocket is developedbetween the posterior sheath and the rectus muscle to accommodate thecontroller assembly 200. A tunneling device can be utilized to createtunnels between the internal components (e.g., the pump assembly 100 andthe controller assembly 200) for the passage of intervening conduits(e.g., the electrical conduit 230) and to create a tunnel between thepocket to contain the controller assembly 200 and the exit location ofthe percutaneous lead 400. The electrical conduit 230 can be inserted inthe tunnel leading to the blood pump assembly 100 and secured to thebulkhead connector 102. The percutaneous lead 400 can be tunneled to thepocket developed for the controller assembly 200, the controllerassembly 200 can be positioned in the pocket, the conduit 230 can besecured to the controller assembly 200 using the bulkhead connector 202,and the percutaneous lead can be secured to the bulkhead connector 204in the controller assembly 200. Pumping may be subsequently initiated(e.g., by placing the telemetry wand 510 over the controller assembly200 and initiating a start-up mode) using power transferred through thepercutaneous lead 400. The optional display 520 can display informationsuch as hemodynamic parameters. After verifying proper functioning ofthe hybrid system 10, the internal power storage device(s) 350 can thenbe enabled and tested. After completion of the operative procedure,chest and abdominal radiographs can be obtained to confirm componentpositioning.

Other Embodiments

While several configurations of the hybrid ventricular assist system 10have been described here, it should be understood that there are manycombinations of pump assemblies, controller assemblies, power storageassemblies, power storage devices, external controllers, external powersources, and external communication devices that can be employed toperform the functions of the system 10 described above. Nevertheless, itwill be understood that various modifications may be made withoutdeparting from the spirit and scope of this disclosure. For example, thehybrid system 10 can include a controller assembly (e.g., the controllerassembly 200, 700, and the like) and a power storage assembly 300 thatboth include rechargeable power storage devices (e.g., the devices 350,360, 365, and the like). In another example, the pump assembly 100 caninclude the controller circuitry (e.g., the controller device 210, thewireless telemetry device 220, and the like) used to control and monitorthe function of the pump 110. As such, such hybrid ventricular assistsystems can be free of a separate controller assembly (such as thecontroller assembly 200, 700, and the like). Furthermore, there are manydevices that can be used as an external communication/controller device.For example, the hybrid system 10 can wirelessly communicate with cellphones, PDAs, laptop computers, tablet computers, desktop computers, andthe like that include the capability for wireless communication.Accordingly, other embodiments are within the scope of the followingclaims.

1. A blood pump system, comprising: a first implantable housingincluding a rechargeable power storage device; an implantable blood pumpindependent from the first implantable housing that supplements thepumping function of a heart, wherein the rechargeable power storagedevice supplies electrical power to the implantable blood pump; and apercutaneous extension, coupled to the rechargeable power storage deviceand adapted to traverse the skin, that is configured to releasablyconnect to an external power supply adapted to provide power forrecharging or supplementing the rechargeable power storage device topower the implantable blood pump.
 2. The system of claim 1, wherein thesystem includes two rechargeable power storage devices that supplyelectrical power to the blood pump.
 3. The system of claim 1, whereinthe blood pump is a ventricular assist device.
 4. The system of claim 1,wherein the system further comprises a second implantable housing thatencloses the blood pump and that includes pump controller circuitry thatcontrols the operation of the blood pump.
 5. The system of claim 4,wherein the system includes a rechargeable battery electricallyconnected to the pump controller circuit for supplying electrical powerto the pump controller circuit.
 6. The system of claim 1, wherein thefirst implantable housing further includes an internal system controllerthat controls the operation of the blood pump.
 7. The system of claim 1,further comprising an external power supply.
 8. The system of claim 7,wherein the external power supply is a battery or a converted AC sourceadapted to supply electrical power for the normal operation of the bloodpump.
 9. The system of claim 1, wherein the percutaneous extensionincludes a plurality of wires that traverse the skin and carryelectrical current to recharge or supply power to the rechargeable powerstorage unit; and an electrical connector coupled to the plurality ofwires and adapted to couple to a portion of the external power supply.10. The system of claim 9, wherein the percutaneous extension furtherincludes a fluid-resistant sheath that is coupled to the electricalconnector and that surrounds the plurality of wires along substantiallythe length of the plurality of wires.
 11. The system of claim 9, furthercomprising a fluid resistant cap adapted to be removably coupled to theelectrical connector for protecting the interior of the electricalconnector from contact with external fluids when the electricalconnector is not coupled to a portion of the external power supply. 12.The system of claim 11, further comprising an internal power sensingfeature that detects an amount of power remaining in the rechargeablepower storage device, the cap or an external end of the percutaneousextension being adapted to emit a light when the power sensing featuredetermines that the amount of power remaining in the rechargeable powerstorage device is less than a minimum threshold.
 13. The system of claim9, wherein the percutaneous extension includes at most four wires. 14.The system of claim 13, wherein the at most four wires comprise tworedundant sets of two wires, wherein each redundant set of wires carryelectrical current to recharge the rechargeable power storage unit. 15.The system of claim 1, wherein the percutaneous extension has across-sectional area that is less than about 0.1 in².
 16. The system ofclaim 1, wherein the first implantable housing has a volume that rangesfrom about 1 in³ to about 20 in³.
 17. The system of claim 1, wherein therechargeable power storage device can supply electrical power for normaloperation of the blood pump for a period of time of at least 30 minutes.18. The system of claim 1, wherein the rechargeable power storage devicecan supply electrical power for normal operation of the blood pump for aperiod of time of at least 2 hours.
 19. The system of claim 1, whereinthe rechargeable power storage device can be recharged from afunctionally depleted state to a fully charged state in less than about1 hour.
 20. The system of claim 1, wherein the first implantable housingfurther includes an implanted telemetering device.
 21. The system ofclaim 20, wherein the system further includes an external monitoringdevice that includes an external telemetering device that communicateswirelessly with the implanted telemetering device.
 22. The system ofclaim 20, wherein one of the internal system controller and the externalmonitoring device is adapted to notify the patient that an amount ofelectrical charge remaining in the rechargeable power storage device isless than a minimum threshold.
 23. The system of claim 22, wherein theminimum threshold is an amount of electrical charge for normal operationof the blood pump for 30 minutes.
 24. The system of claim 23, whereinthe first implantable housing is adapted to vibrate to notify thepatient that the amount of electrical charge remaining is less than theminimum threshold.
 25. A method of using the system of claim 1 whenimplanted within a user, the method comprising: connecting thepercutaneous lead to an external power supply to supply power to theblood pump or to charge the rechargeable power storage device;disconnecting the percutaneous lead from the external power supply for aperiod of at least 30 minutes, the rechargeable power storage devicesupplying power to the heart pump for the period of at least 30 minutes;and reconnecting the percutaneous lead to the external power supply torecharge the power storage device or to supply power to the blood pump.26. A blood pump system, comprising: an implantable blood pump thatsupplements the pumping function of a heart; an internal systemcontroller that controls the operation of the implantable blood pump; arechargeable power storage device that supplies electrical power to theimplantable blood pump, wherein the rechargeable power storage devicecan supply electrical power for the normal operation of the implantableblood pump for a period of time of at least 30 minutes; and apercutaneous extension coupled to the rechargeable power storage deviceadapted to traverse the skin and to releasably connect to an externalpower supply to provide power to supplement or recharge the rechargeablepower storage device.
 27. The system claim 26, wherein the rechargeablepower storage device has a volume that is greater than about 7 in³. 28.A blood pump system, comprising: a first implantable housing includingan internal system controller and a rechargeable power storage device; ablood pump that supplements the pumping function of a heart, wherein thefirst implantable housing is coupled to the blood pump via one or moreelectrical wires, and the rechargeable power storage device supplieselectrical power to the blood pump for the normal operation of the bloodpump for a period of not less than 30 minutes; an external device thatwirelessly communicates with the internal system controller; and apercutaneous extension adapted to traverse the skin and to releasablyconnect to an external power supply to provide power to the rechargeablepower storage device, the percutaneous extension comprising: tworedundant sets of two wires, wherein each redundant set of wires isadapted to carry electrical current to recharge the rechargeable powerstorage unit; an electrical connector coupled to the plurality of wiresand adapted to couple to a portion of the external power supply; awater-resistant sheath that is coupled to the electrical connector andthat surrounds the plurality of wires along substantially the length ofthe plurality of wires.
 29. The system of claim 28, wherein thepercutaneous extension has a cross-sectional area that is less thanabout 0.1 in².
 30. The system of claim 28, wherein the first implantablehousing has a volume that ranges from about 1 in³ to about 20 in³.